Rotate Array

This is No.189 problem in LeetCode.

The problem description is:

Given an array, rotate the array to the right by k steps, where k is non-negative.

Example 1:

Input: [1,2,3,4,5,6,7] and k = 3
Output: [5,6,7,1,2,3,4]
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]

I find a solution online and I think it is a classical approach to array rotate problem.

I am gonna put the code below, it's easy to understand and very useful to do similar problems.

public class Solution {
    public void rotate(int[] nums, int k) {
        k = k % nums.length;
        reverse(nums, 0, nums.length-1);
        reverse(nums, 0, k-1);
        reverse(nums, k, nums.length-1);

    private void reverse(int[] nums, int i, int j){
            swap(nums, i, j);

    private void swap(int[] nums, int i, int j){
        int tmp = nums[i];
        nums[i] = nums[j];
        nums[j] = tmp;

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